Methods Randomsample were obtained from the whole population by multiple stratified cluster and 1 320 objects were surveyed in their own homes by questionnaires.
方法采用多阶段整群抽样和配额抽样相结合的方法，对深圳市1 320名居民进行入户问卷调查。
2
Methods: Stratifiedrandom cluster sampling method was used to determine the survey sample.
方法：以分层随机整群抽样的方法，确定调查样本。
3
Define and apply techniques for assuring data accuracy and integrity such as random sampling, stratified sampling, sample homogeneity, etc.